If your iPhone/iPad battery seems to run down frequently, go to Settings > General > Background App Refresh and check what's running in the background.

FACEBOOK
Without a doubt the biggest battery hog. Not only does it tear through the battery when it's actively being used, but it's also a huge hog when it's in the background too.
I'm not a particularly heavy Facebook users so I can't imagine how bad it must be for people who are on Facebook a lot.
My advice is to either close the app when it's not in use, or prevent it from working in the background (Settings > General > Background App Refresh). Alternatively, you could access Facebook via a browser.

GOOGLE CHROME

Apple has done a good job of optimizing the code in its apps. Google, on the other hand, has a long way to go. Chrome is a solid browser, but it uses many times more power than the built-in browser. Yes, you read that right. We're not talking about a small difference here. If you want the best battery life, use Safari.

TWITTER
Here's another app that not only rips through battery life while you're using it, but it's also continually polling for new tweets when in the background. The more people you follow, the harder the app works and the more it hits the battery.
My advice is to either close the app when it's not in use, or prevent it from working in the background
(Settings > General > Background App Refresh).

GOOGLE MAPS
Another example of being hit with a penalty for using a third-party app over the stock app. But since the Google Maps app offers a great deal more functionality compared to Apple's Maps app, it's not surprising that it's such a battery hog. After all, there's no such thing as a free lunch.

SKYPE
Here's another app that not only burns through battery life during use - it's the heaviest app of its kind - but it also continues to hammer at the battery when it's in the background.
You could disable the app in the background, but then you're only going to be available when the app is in the foreground. Alternatively, if you could try to convince your family/friends/colleagues to use iMessage and FaceTime instead.

CONCLUSION
• Stock apps are the better choice if you want to get the most from your battery.
• Social media apps are hard on the battery
• Certain apps running in the background can be a real drain on the battery, so consider shutting off their access using the Background App Refresh setting.
• To find out how your apps are behaving, keep an eye on the battery usage information (Settings > Battery).